1. Field of the Invention
The present invention relates to an ink-jet printhead, and more particularly, to a bubble-jet type ink-jet printhead.
2. Description of the Related Art
The ink ejection mechanisms of an ink-jet printer are largely categorized into two types: an electro-thermal transducer type (bubble-jet type) in which a heat source is employed to form a bubble in ink causing ink droplets to be ejected, and an electromechanical transducer type in which a piezoelectric crystal bends to change the volume of ink causing ink droplets to be expelled.
Meanwhile, a bubble-jet type ink-jet printhead having an ink ejector needs to meet the following conditions. First, a simplified manufacturing process, the low manufacturing cost, and high volume production must be allowed. Second, to produce high quality color images, creation of small and minute satellite droplets that trail ejected main droplets must be prevented. Third, when ink is ejected from one nozzle or ink refills an ink chamber after ink ejection, cross-talk with adjacent nozzles from which no ink is ejected must be prevented. Fourth, for a high speed print, a cycle beginning with ink ejection and ending with ink refill must be as short as possible.
However, the above conditions tend to conflict with one another, and furthermore, the performance of an ink-jet printhead is closely related to the structures of an ink chamber, an ink channel, and a heater, the type of formation and expansion of bubbles associated therewith, and the relative size of each component.
In efforts to overcome problems related to the above requirements, ink-jet print heads having a variety of structures have been proposed in U.S. Pat. Nos. 4,339,762; 4,882,595; 5,760,804; 4,847,630; and 5,850,241, European Patent No. 317,171, and Fan-Gang Tseng, Chang-Jin Kim, and Chih-Ming Ho, “A Novel Micoinjector with Virtual Chamber Neck”, IEEE MEMS '98, pp.57-62. However, ink-jet printheads proposed in the above patents and literature may only satisfy some of the aforementioned requirements but do not completely provide an improved ink-jet printing approach.